In Search of High Reliability in Printed Board Fabrication for Medical Device Applications

By John Perry, Director of Printed Board Standards & Technology It has been well known that for many years IPC has provided a trio of performance classifications in its suite of standards and specifications for the design, fabrication, assembly and acceptance of printed boards and printed board assemblies. Intended to reflect differences in producibility, complexity, functional performance requirements and verification through inspection and testing, IPC has given end users (OEMs) the authority to specify which IPC performance class the printed boards and assemblies must adhere to for their product. This model isn’t without its limitations, however. A printed board fabricated in accordance with Class 3 (high performance/harsh environment electronic products) requirements from IPC-6012D, Qualification and Performance Specification for Rigid Printed Boards (or the corresponding IPC-6013D for flexible and rigid-flexible printed boards) can be subjected to very different operating environments. A Class 3 printed board intended for usage in a space exploration vehicle on a one-way trip to Jupiter is going to experience a very different set of thermal cycles compared to a printed board utilized in an automotive under-the-hood application. The same can be said for exposure to vibration for a printed board utilized in an oil-drilling operation compared with that of a marine application. Understanding this, IPC has already published a set of addendums to some of its most widely used standards for specific industry segments, including space and military avionics and automotive, where exceptions have been made to the baseline IPC Class 3 requirement in the parent standard or specification. Never has a case for this approach, however, been more evident than with respect to printed boards utilized in medical device applications. Will the “traditional” IPC Class 3 performance class be sufficient for printed boards used in applications where interruptions to service may result in the loss of life or permanent bodily harm to a patient or equipment operator? If an exception to an IPC Class 3 performance attribute were developed for medical device product, would that exception need to be further sub-divided between “standard” sized printed boards utilized in diagnostic or patient monitoring equipment (e.g. electrocardiograph or blood analyzer) and “micro-PCBs” utilized in implantable devices (e.g. neurostimulator or gastric stimulator)? Sampling frequencies of production printed boards or test coupons within an overall production “lot” for IPC Class 3 product have traditionally been based on the needs of defense products in ground, airborne or space applications where production lots are relatively small. These traditional IPC sampling frequencies for production lot acceptance, however, fall apart when dealing with production runs in the thousands or tens of thousands of printed boards, as in the case of medical device product. Recognizing all of this, key members of a new IPC task group will be giving a presentation at the Medical Design and Manufacturing (MD&M) West Expo in Anaheim, Calif. on Tuesday, February 6, 2018, titled “Do you Really Know if Your Medical Device PCBs Comply with Required Qualification Standards?” Located in the Tech Theater on the show floor of the Anaheim Convention Center and scheduled for 10:30 AM local time, the presentation will address: • Medical and Biological Innovations Across the Decades • Present Day Medical Device Electronics • Density Trends in Array Packaging for Medical Device Electronics • The Cost of Quality of Electronic Failures to Major Medical Device Manufacturers • Existing Standards for Medical Device Electronics and the Gap in Conformance Assessment for Printed Boards • Intended Scope for IPC-6012 and IPC-6013 Medical Device Addendums If you are attending or plan to attend the MD&M West event, IPC encourages those of you involved in printed board manufacturing and procurement to attend this session and learn how we are pulling together OEMs, PCB design engineers and quality engineers and managers at the PCB fabrication level to help put together the new IPC-6012DM and IPC-6013DM Medical Device Addendums to our printed board qualification and performance specifications for rigid, flexible and rigid-flexible printed boards. Please note that while members of this IPC task group are presenting at MD&M West, IPC is neither sponsoring nor directly involved with this event, and therefore IPC membership has no bearing on registration costs for this event under UBM Management. For additional information on the IPC-6012DM and IPC-6013DM Medical Device Addendum efforts, please contact me, at JohnPerry@ipc.org or +1-847-597-2818.